Treating partial-oxidation products



Patent July 2 3 l92 rosnrn nrnr JAMES, or nrrrsnnnen, rrvnnrn.

TREATING PARTIAL-OXDQATION No Drawing.

In my copending applications Serial No. 272,567, filedJanuary 22, 1919; Serial No. 435,355, filed January 6, 1921, and others I have described methods for the vapor phase 5 partial oxidation of hydrocarbons, including petroleum, shale oil, the low temperature distillation of coal and the like, consisting mainly'of alipha tic hydrocarbons.

In sueh methods, the liquid hydrocarbons are vaporized, mixed with a regulated proportion of oxygen, usually in the form of air, and then passed through a hot conversion zone at a temperature ranging between 270 C. and 500 G., depending upon the products 1 whose preponderance is desired. In the hot v conversion zone,-the vapor mixfture is preferably subjected to contact with catalytic ma- I terial consisting of the oxides or compounds of high-melting-point electronegajtive lowatomic volume metals; These metals appear on the Lothar Meyer diagram of the periodic series beginning on the descending side'of the third peak, descending side of the fourth peak and thedescending side of further peaks developed since the date of this diagram. The class includes the following metals :titaniurn, vanadium, chromium, manganese, zirconium, niobium, molybdenum, tantalum, tungsten and uranium.

As set forth in my copending application, Serial No. 435,355, the vap'or'mixture may be and preferably is passed ovgr a plurality of layers, air orroxygen being supplied between some or all of the layers. -Tllfill proportion is varied according to the catalyst used, the temperature and the speed of the current. The more activethe satalyst, the nearer the air can approach the theoreticalamount; and the same as to temperature." Steam may also be supplied in regulated proportions. The temperature is below that of continuous selfsustained combustion and will vary according to the'hydrocarbon treated, the catalyst .rused, etc. and if a predominanceof aldehyde, is desired,-will usually'be lower-than that where a predominance of aldehyde fatty acids-is desired The condensed product oi this treatment .Willpontain alcohols, aldehydes, and oxygen- :iated; acids in varying roportions, depending nithfe conditions 0 the the hydro- Application filed ma 1a, 1928. awn-no; matte."

carbon; treated, etc. As the liquid hydrocarbon treated contains, h drocarhons of varying molecular weight, t e product will contain alcohols, aldehydes and acids of varying molecular weights. The aldehydes are probably in part monoaldehydes and in part dialdehydes. i r

My present invention is designed to further treat such product of my main process and so to further oxidize the constituents thereof, or portions of them, to give a better type or class of products for industrial uses, such as soap making, etc. When the original product is saponified in the ordinary way, the soapsproduced are dark in color and have apeculiar odor. Thecolor and odor are both greatly improved by the further oxidation treatment 7 of my pmsent invention. This application is in part a continuationof my copending a plication, Serial No. 2 8l,l2+, filed March 1919. i 5 I The acids of my main process, particularly in the higher boiling ranges, are aldehydic' in character and the congenericoil (the nonsaponifiahle'oil) of the product consists almost completely of bodies containing oxygen. Hence the condensed roduct is amenable to furtheroxidation, which my present inven tionis designed to accomplish. so

Under the preferred form of my presentprocess, I propose to oxidize the oxygenated acids of varying molecular weights to dihasic acids and the aldehydes of varying molee'ular weights to ordinary monobasic' fatty acids or to dibas'ic acids (depending upon whether the aldehyde is'a monoor a di-aldehyde).-

If the reaction is continued suficiently long,-

and use the remainder for further oxidation, I

Thus I prefer to distil off '1 The further oxidation may be carried out in several ways, but I prefer to use chemical oxidation methods, such for example as set forth in the following three examples:

I. This is chromic acid oxidation and may be carried out by. the use of a solvent (for both the product and the chromic acid) or without such solvent. In the latter case, a suspension of the organic product, and a water solution of the chromic acid, is used.

An example of the suspension method is as follows: A sample consisting of 100 c. c. of a condensed oxidation product made by the catalytic air oxidation of unrefined spindle oil (mid-continent), and containing approximately of organic acids, was

treated in a suspension of one to four sulphuric acid with a half saturated solution of chromic acid in water. The suspension of oil oxidation product was, maintained by vio: lent mechanical agitation and the'chromic acid solution was run'in slowly, care being taken that the temperature did not rise above 40 C. After the chromic treatment, when a test for free chromic acid was obtained which persisted for one hour, the reaction was :stopped, the organic product separated,

washed and tested for the quality and amount of. fatty I acids. It was found that the fatty acids had risen from 30% to 48%, and that only a very small amount of aldehydic substances were left. The, soaps, even when made by boiling with caustic Potash or caustic soda solution were of a yellowish cream color, in strong contrast to the dark brown soaps formed by the original catalytic oxidation acids.

In another trial with the same catalytic oxidation product, but by the use of 200 c. c.

of glacial acetic acid as a solvent and a chrom1c acid solution made bymixing one volume of a-saturated water solution of chromic acid with four volumes of glacial acetic acid, and a temperature of 27 to 32 (1., the other conditions as to agitation, addition of oxidant,

-etc., being the same as in the preceding work a cyclic electrolytic regeneration re-.

covery process for the chromic acid, this method of making fatty acids has great pos- 1 vsibilities.

II: This method of carrying out the chemical oxidation of the product obtained by the first or catalyticoxidation is, based on the oxidizing action of chlorine, and further, on.

the direction of h ochlorous acid decomposition towards the ormation of hydrochloric acid and oxygen;

When chlorine gas is assed into water, hypochlorous acid (HOLI) is one of the products.

H O+C1 =IICl+HOGI 2HOOl+catalyst c001 etc.)- 2HC1+O This reaction applied to calcium hypochlorite in water solution is the 'well known La Voisite process for making oxygen.

I hav'eapplied this reaction to a water or dilute acid suspension of the catalytic oxidation mixture to accomplish the same purpose as that of Method I.

The following example will show how this reaction is applied.

A mixture gvas. made of the following proportions:

lQO c. c. spindle oil catalytic oxide mixture.

500 c. c. Water.

100 c. c. 2% cobalt chloride solution.

50c. c. concentrated hydrochloric acid solution.

- A vigorous mechanical stirring brought about a good suspension-of the oxidized oil in'the water solution. A slow stream of chlorine gas was passed into the suspension for six hours at 95 C. Some cobalt soaps separated out under these conditions. Whilethe character of the acids recovered from this mixture was nottas good as in Method 1,

the acid had been increased to approximately 50%, (some aldehyde bodies were 'still pres oxidation). This method can be easily used to increase the acid content of a catalytic air oxidation mixture, since the chlorine is available and cheap.

III. This method, which I consider the best for my present purposes, is based on the properties, physical and chemical, of the-oxides of nitrogen and of nitric andnitroils acids. Nitric acid itself is a violent oxidizing agent. The oxides of nitrogen, nitric oxide (NO), nitrogen dioxide (NO,) are soluble in nitric acid and in nitric acid water solutions down to certain concentrations. Nitric acid readily breaks. down, these oxides being the main products. Now the lower of these oxides '(NO readily takes on oxygen from the air going up to the dioxide (NQQ The dioxide is an energetic oxidizing a cut.

out or had been formed because of incomplete Having, as a medium, ilute nitric acid to 1 act as a solvent for these oxides and also to provide a menstruum for the suspension of the organic material to be oxidized, we have all the conditions'for what. is really an airoxidation. of the catalytic, oxidation mix-,-

ture. The nitric 4 acid and the nitrogen oxides function about the. same as they do in the lead chamber process for making sulphuric acid.

rather lowfor the best results; then by bubbling air through the agitated suspension, the

desired oxidation can be carried almost to completion.

The followingexamplewill serve to illustrate the application of this method A mixture was made up of the following pro'portions:

300 c. c. catalytic oxidation mixture made from a. 50: 50-gasoil-wax distillate blend.

500 c. c. nitric acid solution, 22%. This mixture was violently agitated by a mechanical stirring device and air bubbled in violently for twelve hours, the temperature not being allowed to rise above 50 0., being kept most of the time at 45 C. The oxidation mixture gradually changed in color from the original dark brown to a light brick red.

When the oxidation is complete, the greater part of the organic acids will sink in water. In this example, the bottom layer, represent ing) 80% of the total, ,was completely saponitie is and the top layer, representing 20% of the product, was 88% saponifiable. This shows that practically 96% of the material fed into the original catalytic air oxidizer had been acted on by the oxidation, as the action on the ori 'nal hydrocarbons under these mild oxidizing conditions is very slight.

I propose to carry out this reaction on a large scale by blowing air successively through a long connected series of such'mixtudes in properly arranged apparatus. The small amount of nitrogen oxides escaping from the last vessel of the train -can be easily absorbed in an alkali tower and the nitric and nitrous acids recovered; or the Gay-Lussac tower method used by the manufacturers of sulphuric acid may be used for this recovery.

I may also add certain oxides to the acid in order to aid in theabove reaction, such as vanadium pentoxide, molybdenum trioxide, etc.

In all the above methods, it should be. noted that a goodtotal recovery is obtained-from 85 to 95% being the usual practice. I

I may also in each of the foregoing methode-remove the last of the aldehydic bodies at the-end of the second? oxidation by long agitation of the suspended acids in a rather concentrated sodium bisulphite solution.

Final purificationeof the ordinary vacuum or vacuum-steam distillation methods may be applied to the products made by any of the above schemes. 7 r

of my main process,-mix the vapor with oxygen (preferably in the form of air) and subject the mixture to a catalytic partial oxidation, using steam also in some cases, as set forth in my ,copending' application Serial No. 281,124, filed March 7, 1919. In this step, which is generally the same as the main original process step, a catalyst may or may not be used, though I prefer to employ it in' the hot reaction zone. In this step, the carbon compounds of the original product ai'e further oxidized, the aldehydes being largely converted into acids. The multiple-screen system of my copending application Serial No. 435,355 maybe advantageously employed in this further oxidation step, and as in the original process, the air is regulated and the catalyst maintained Within a definite'range of temperature, depending upon the average molecular weight of the mixture treated, which, in turn, depends upon the oil fraction treated in the main process. Here again, the temperature is preferably kept below that of continuous self-sustained combustion, though such may occur and completely oxidize a part of the vapor mixture. This, however, lowers the yield. V

The proportions of air and aldehyde vapor should be voided according to the particular catalyst used, the temperature employed and the speed of the current. The more active the catalyshthe nearer the proportion of air can approach the theoretical amount. same is the case as to raising the temperature of the catalyst. The more active the catalyst or the higher the temperature, the nearer the proportion of air may approach to the theorcticalamount. With less active catalysts, or with a lower temperature, the greater is the proportion of air which should be used. The catalysts used are preferably in the same group as those used in the original process. The original process is preferably carried out to produce a predominance of aldehydes, the temperature being kept some- "what lower than that for producing aldehyde fatty; acids, for example, around 250 C. for Pennsylvania kerosene.

I will now describe 'a specific exampleof bestos, held between parallel screens, the active material packed in a disk-shaped space l 0, diameter and 1.25-c. thick.

(B) Aldehyde mixture treated: A mixture of aliphatic aldehydes made from Penn- The sylvania petroleum kerosene having the following composition:

(F) Temperature 300 to 330 0. Results." 49 c. c. of liquid product recovered which has the following analysis:

. Per cent. Aldehyde fatty acids "'65 Aliphatic aldehydes ..i 31.5 Hydrocarbons (aliphatic) 3.5

In addition, from the water-absorbing system, a ldehyde fatty acids soluble in Water are recovered in the-form of their calcium salts, amounting to 2.64 grams.

In using this vapor phase oxidation method for the original products containing alcohol and aldehydes and aldehyde acids, the lighter portion or portions of the original product may be distilled off, before the further oxidation step is applied to the heavier portions.

The temperatures used in the oxidationstepsvary from 230C. to500 (1., depending upon the fraction originally treated, theamount of air, etc.

I consider myself the first to discover a practical processfor treating mixtures of aliphatic aldehydes of Varying molecular weight and converting them into the corresponding acids; and alsothe first to-oxidiz'e a mixture containing alcohols and aldehydes ant:1 convert portions of the aldehydes into aci s.

In the chemical oxidation step, true fatty acids are produced along with dibasic acids. By the term air in my claims, I intend to cover air or pxygen or any gas mixture containing free oxygen.

A catalyst may or may not be used in the vapor phase oxidation step; the apparatus used may be widely varied, the chemical oxidant used may be changed and other changes may be made without departing from my invention.

Claims to the salts of dibasic acids and methods of making them are not included in this case as such are covered in my copendin application Serial No. 549,567 fiiled April 4, 1922, for method of making dibasic acids and compounds thereof.

1.- The method oftreating a partial oxidation mixture which is liquid at normal temperature and pressures containing aliphatic aldehydesof different molecular weights consisting in oxidizing at least a portion of said aldehydes into aci 1 aldehydes and oxygenated organic acids of different molecular weight-s consisting in 2. The method of treating a partial oxidation mixture which is liquid at normal temperatures and. pressures containing alcohols and aldehydes of petroleum-like hydrocarbons, consisting in oxidizing at least a portion of the aldehydes in the mixture into acids.

3. The method of treating a partial oxidation mixture which is liquid at normal temperatures and pressures containing aliphatic oxidizing at least a portion of said aldehydes into acids.

4. The method of treating a mixture containing oxygenated hydrocarbons of different molecular weights, consisting in subjecting the same to further oxidation in the, liquid phase in the presence of a highly active oxidizing agent.

5. The method of treating a partial oxidation mixture which is liquid at normaltemperatures and pressures containing alipliatic aldehydes and other carbon compounds of petroleum-like hydrocarbons consisting in applying an oxidant thereto and oxidizin at least a portion of the aldehydes into aci s. v v i 6. The method of treating a partial oxidation mixtureavhich is liquid at normal tem peratures and pressures and containing oxygenated hydrocarbons of different molecular weights including aldehydes, consisting of subjecting the same while in the liquid phase to further oxidation in the presence of ahighly active oxidizing a out to convert at 1-00 least a portion of the al ehydes into fatty acids.

.r' "7; The method of treating a partial oxidation product containing alcohols and aldehydes of different molecular weights, 0011- sisting of subjecting the same while in the liquid phase to a highly active oxidizing agent. v 8. The method of treating a partial oxidation product containing aliphatic-aldehydes and oxygenated organic acids of different molecular weights, consisting in oxidizing at least a part ofthe aldehydes into fatty acids and the acids into dibasic acids.

9. As a new article of manufacture,.a prodnet of an oxidation process containing straight chain fatty acids and dibasic acids of different molecular weights. v

10. Asa new article of manufacture, an oxidized mixture containing aldehydic bodies 1 0 and dibasic acids ofidifferent molecular weights. 1

11. As a new article of manufacture, the

highly oxidized product resulting. from 2 product containing similar bodies of different molecular weights and being free from aldehyde fatty acids.

12. As a new article of manufacture. the more highly oxidized roduct resulting from further oxidation oi previously oxidized liquid hydrocarbons, said product containing a mixture of dibasic acids of different molecular weights mixed-with other acids.

13. The process consisting in oxidizing previously formed oxygenated acids of petroleum-like hydrocarbons into dibasic acids.

14. The process consisting in oxidizing previously formed oxygenated acids of petroleum-like hydrocarbons into (libasic acids while'in suspension.

15. The process consisting in oxidizing a mixture of oxygenated acids and aldehydes, and changing the acids to dibasic acids and some aldehydes to fatty acids.

16. The method consisting of treating a previously formed mixture of oxygenated acids of different molecular weights with a highly active oxidizing agent and producing a mixture of dibasic acids of different molecular Weights.

17. The method consisting of partially oxidizing mineral hydrocarbons while in the gaseous phase, condensing a part of the prodnot, and then further oxidizing the condensed product by a higl ily active oxidizing agent while in the liquid phase.

18. As a new article of manufacture, the mixture of dibasic acids produced by oxidizing oxygenated organic acids obtained by gaseous phase partial oxidation.

19. As a new article ot'manufacture, the ll'liXt-IHC of dibasic acids produced by oxidizing oxygenated organic acids obtained by gaseous phase partial oxidation. said mixture also containing other compounds derived by said further oxidation".

20. As a new article of manufacture, thc mixture of dibasic acids produced by oxidizing oxygenated organic acids obtained by gaseous phase partial oxidation, said mixture also containing other aeidsderived' by said further oxidation.

21..Ihe method of chemically oxidizing liquid aldehydes produced by partial oxidation of hydrocarbons, consisting in treating them witha highly active oxidizing agent.

In testimony whereof I have hereunto set my hand.

J OSEPH HIDY JAMES. 

